Acoustical devices



Nov. 29, 1960 W. HAERTHER, JR 2,962,109

ACOUSTICAL DEVICES Filed Nov. 25, 1957 30 a" 23 J 4 2 201 59 f f I) lv 1 IN V EN TOR.

" 2,962,109 Patented Nov. 29, 1960 2,962,109 ACOUSTICAL DEVICES William W. Haerther, Jr., Geneva, Ill., assignor to Hawley Products Company, St. Charles, 111., a corporation of Delaware Filed Nov. 25, 1957, Ser. No. 698,467 2 Claims. (Cl. 181-32) This invention relates in general to acoustical devices and, more particularly, to improved types of sound reproducing diaphragms.

It is a primary object of this invention to enable a novel polygonal-shaped acoustic diaphragm to be afforded.

In the construction of polygonal-shaped acoustic diaphragms of the type with which this invention is primarily concerned, a concave vibratile portion is normally atforded which has a polygonal-shaped lateral edge, from which edge a flexible flange or rim extends laterally outwardly to thereby movably mount the vibratile portion for movement axially of the concavity.

Polygonal-sha-ped diaphragms have various advantages over diaphragms of other shapes, especially for particular uses or installations. For example, rectangular-shaped diaphragms are particularly well adapted for use in speakers which it is desired to mount in relatively long narrow spaces such as, for example, behind the dashboards of automobiles, or the like.

However, polygonal-shaped diaphragms heretofor known in the art have commonly had inherent disadvantages such as, for example, affording poor sound reproduction; affording insufficieut excursion of the vibratile portion; not affording uniform oscillation of the vibratile portion; and the flange or rim portions thereof tending to crack or break out at the corners, or the like. It is an important object of this invention to overcome such disadvantages.

Another object of this invention is to increase the excursion of vibratile portions of polygonal-shaped diaphragms in a novel and expeditious manner.

Another object is to aiford a novel polygonal-shaped diaphragm having good sound reproducing or producing characteristics.

Yet another object of this invention is to enable the vibratile portion of polygonal-shaped diaphragms to oscillate uniformly.

A further object of this invention is to increase the effective life of polygonal-shaped diaphragms.

Another object of this invention is to eliminate the cracking or breaking out of the corners of polygonalshaped diaphragms.

Yet another object is to increase the useful life of polygonal-shaped diaphragms.

Other and further objects of the present invention will be apparent from the following description and claims, and are illustrated in the accompanying drawings which, by way of illustration, show the preferred embodiments of the present invention and the principles thereof, and what I now consider to be the best modes in which I have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

Fig. 1 is a top plan view of a diaphragm embodying the principles of the present invention;

Fig. 2 is a longitudinal sectional view taken substantially along the line 2--2 in Fig. 1;

Fig. 3 is a detail sectional view showing a portion of the diaphragm shown in Fig. 2, with a portion thereof removed;

Fig. 4 is a top plan view of a modified form of the diaphragm;

Fig. 5 is a longitudinal sectional view taken substantially along the line 5-5 in Fig. 4;

Fig. 6 is a detail sectional view, to somewhat enlarged scale, taken substantially along the line 6-6 in Fig. 4;

Fig. 7 is a detail sectional view showing a portion of the diaphragm shown in Fig. 5; and

Fig. 8 is a detail top plan view of a modified form of the invention.

A diaphragm 1, embodying the principles of the present invention, is shown in Figs. 1 to 3 of the drawings to illustrate one form of diaphragm contemplated by the present invention.

In general, the diaphragm 1 embodies a concave vibratile portion 2 connected by an undulated portion 3 to a substantially rectangular-shaped supporting flange or rim 4, adapted to be clamped between the supporting braces, or the like, of a speaker.

The vibratile portion 2 is of a convex-rearwardly shape, flaring forwardly and generally laterally outwardly of a tubular-shaped nipple 5 at the centrally located apex thereof to a substantially rectangular-shaped base 6, having two parallel straight short ends 7 and 8, connected together by two straight parallel longitudinally extending sides 9 and 18 which are perpendicular to the ends 7 and 8, Figs. 1 and 2.

The vibratile portion 2 of the diaphragm 1 embodies a convex-rearwardly, substantially elliptical central portion 11, the major axis of which extends along the longitudinal center line of the diaphragm 1. The tubular apical portion 5 is disposed at the center of the ellipticalshaped portion 11, and the latter slopes forwardly in all outer directions from the apical portion 5. The lateral sides of the elliptical-shaped portion 11 terminate at the longitudinally extending sides 9 and 10 of the vibratile portion 2, whereas the ends of the elliptical portion 11 terminate in inwardly spaced relation to the ends 7 and 8 of the vibratile portion 2, Fig. l. The ends of the elliptical-shaped portion 11 terminate approximately onehalf of the distance from the adjacent side of the apical portion 5 to the respective end 7 or 8 of the vibratile portion 2, Fig. 2.

Two forked ribs 12 and 13 extend from the respective ends of the elliptical-shaped portion 11 toward the ends 7 and 8, respectively of the vibratile portion 2. The forked rib 12, which extends from the elliptical portion 11 toward the end 7 of the vibratile portion 2, embodies a main branch 14 which terminates at its free end approximately midway between the end 7 of the vibratile portion and the adjacent end of the elliptical portion 11. The forked rib 12 also embodies two end branches 15 and 16 which extend outwardly from the free end of the main branch 14 in outwardly diverging relation to each other toward the corners of the vibratile portion 2 formed by the junction of the end 7 with the longitudinal sides 9 and 10, respectively.

The forked rib 13 is identical in construction to the forked rib 12 except that it is a mirror image thereof. It embodies a main branch 17 which extends'toward the end 8 of the vibratile portion 2 from the adacent end of the elliptical portion 11, the free end of the main branch 17 terminating approximately midway between the end 8 and the adjacent end of the elliptical portion 11. From the free end of the main branch 17, two end branches 18 and 19 project toward the corners of the vibratile portion 2 formed by the junction of the end 8 with the longitudinal sides 9 and 10, respectively.

Each of the ends 7 and 8, and each of the sides 9 and 10, of the outer edge portion 6 of the vibratile portion 2 issubstantially L-shaped in cross-section, Fig. 2, embodying a laterally extending gluing strip or flange 20, from the inner edge portion of which another flange 21 projectsrearwardly.

Throughout their lengths, the main branches 14 and 17 of the forked ribs 12 and .13 slope forwardly from their junction'with-the elliptical portion 11, at substantiallythe same rate as the elliptical portion 11, Fig. 2. The end branches 15 and 16 of-the forked rib 12, and the end branches 18 and 19 of the forked rib 1-3, extend laterally outwardly from their junction'with the main branches 14 and 17, respectively, to their junction with the flange 2-1'of the edge portion-60f the vibratile portion 12, with substantially no forward slope, Fig. 2.

Adjacent-to the end 7, the vibratile portion 2 has a portion 22 ,whichis disposed between the end branches 15 and 16. The portion'22,'slopes gradually outwardly from-thefree end of the main branch 14 to its junction with'theflange 21 on the-end 7 of the-vibratile portion 2. At this same end, the vibratile portion 2 embodies two other portions 23 and 24, disposed on opposite sides of the main branch '14, between the end branch 15 and the elliptical portion'-11, and between the branch 16 and the ellipticalportion '11, respectively. Each of these portions 23 and 24 slopes gradually outwardly from the sides of the main branch 14 to their junction with the flanges 21 of the sides 19 and 10, respectively, of the vibratile portion 2.

At the other end of the vibratile portion 2, portions 25, 26 and 27 ,are embodied, which are similar to the portions 22, 23 and :24, respectively. The portion 25 is disposed'between the end branches 18 and 19, and slopes gradually outwardly from the free end of the main branch 17 to the flange 21. of the end 8 of the vibratile portion 2. The portion 26 is disposed between end branch 18 and the elliptical portion 11, and slopes gradually outwardly from the side of the main branch 17 to the flange 21 of the side '10 of the vibratile portion 2. The other portion 27 is disposed'between the-end branch 19 and the elliptical portion 11, and slopes gradually forwardly from the side of the main branch 17 to its junction with the flange portion 21 of the side 9 of the vibratile portion2.

The vibratile portion ,2 of the diaphragm 1 is preferably of one-piece construction, and may be made of any suitable material vsuch as, for example, accreted fibrous material, and may be in the form of relatively thin flexible sheet material. The forked ribs .12 and 13, and the elliptical portion 11, are preferably of the same thickness as the remaining portions of the vibratile portion 2, and.are so constituted and arranged that, in operation, the vibratile portion 2 tends to vibrate as a unit throughout-its length and breadth.

In thediaphragm 1 shown in Figs. 1-to 3, inclusive, of the drawings, the flange v4 isconstructed of four-separate strips 28, 29,30 and 31 of material secured to the ends 7 and -8, and the sides 9 and 10, respectively, of the vibratile portion 2. Each of the strips 28-31 embodies an outer edge portion 32 and an inner edge portion 33 connected togetherby an undulated portion 3, Fig. 2. The strips 28-31 are of flexible construction and may be made of any suitable material such as, for example, cloth impregnated with a suitable phenol formaldehyde resin and heat set in that condition to aflord the undulated portion 3. The inner edge portions of the strips 28-31 are secured in juxtaposition to the lateral flanges or gluing flanges of the ends 7 and 8 and the side walls 9 and 10, respectively, of the vibratile portion 2 by a suitable adhesive such as, for example, glue or a suitable thermoplastic resin. The strips 28-31 are the same length as theends 7 and 8 and the sides 9 and 10 of the vibratile portion 2, respectively, and are so disposed on the respective flange portions 20 to which they are attached that they terminate at their opposite ends in alignment with the corresponding ends of the respective flanges 20.

With this construction, it will be seen that open corners 34 are alforded in the flange 4 and the undulated portion 3 of the diaphragm 1 between each adjacent pair of the strips 2831.

One of the common disadvantages of polygonal-shaped diaphragms heretofore known in the art, which embodied outer edges having corners thereon, and which embodied laterally projecting supporting flanges, "has been that the vibratile portion thereof did not vibrate or oscillateas a unit. Another common disadvantage has been that such diaphragms have tended to crack and break out at the corners. I have found that by forming an opening at the corners of the diaphragm, outwardly of the vibratile portion and extending at least partially through the undulated portion, unitaryvibration of'the'vibratile portion is improved and improved performance of the diaphragm is aflorded. Also, I have found that such construction tends to overcome the tendency of the diaphragms to crack or break-out -atthecorners,'and prolongs the life of such polygonal diaphragms.

According to the present theory, it is believed that the adjacent side 'portions of polygonal-shaped diaphragms, suchas, for example, the adjacent end portions and longitudinal "side portions of rectangular-shaped diaphragms, have heretofore tended to vibrate relative to each other, thus tending to distort .the reproduction of sounds and to flex, and eventually tear or break, the junction between the two portions, whereas, with diaphragms constructed in accordance with the present invention, the adjacent'end and side portions are permitted, at least in part, because of the openings 34, to flex and vibrate as a unit to thereby improve the tone reproducing qualities and effectively reduce the tendency of the diaphragms to tear at the corners.

In the formation of the diaphragm '1, the tubularshapednipple 5 is normally formed with a cap portion 35 closing therear end thereof, and this cap portion 35 may be clipped or otherwise removed therefrom prior to mounting the diaphragm 1 in a suitable speaker, orthe like,Fig. 3.

In the operation of the diaphragm 1, the outer edge portions 32 of the flange 4 may be suitably clamped between supporting braces, or the like, in a speaker, with the vibratile portion '2 movably supported on the flange 4 by the undulated portion 3, and with the voice coil of the speaker mounted on the :tubular member 5. With the diaphragm 1 so mounted in a speaker, remarkably true reproduction or production of sound is afforded thereby, and a long-life diaphragm is afforded, which may be readily and economically produced commercially.

It has been found that with the combination elliptical centerforked rib construction of the vibratile portion 2 of the diaphragm 1, the structural strength of the vibratile portion 2 is so distributed that'the latter portion tends to vibrate substantially as a unit on the undulated portion 3 by which it is connected to the flange 4 when driven by a suitable member, such as, for example, the voice coil of a dynamic speaker connected to the nipple 5 of the diaphragm 1.

In Figs. 4, 5 and 6 of the drawings, a modified form of diaphragm 36 is shown, which, like the diaphragm 1, embodies a concave vibratile portion 37 connected by an undulated portion 38 to a laterally-outwardly projecting flange or rim 39. The diaphragm 36 is convex-rearwardly in shape, and embodies a centrally disposed tubularshaped apical portion'40. Like the diaphragm 1, the diaphragm 36 also embodies a centrally disposed elliptical portion 41, from the opposite ends of which project two forked ribs 42 and 43. However, the elliptical portion 41 of the diaphragm 36 projects only approximately one- :fourth of the distance from the tubular portion'40 toward the opposite ends 7 and 8, respectively, of the vibratile portion 37. The forked rib 42 of the-diaphragm 36 embodies a main branch 44 and two end branches 45 and 46, and the forked rib 43 iembodies amain branch 47 sesame and two end branches i8 and W. The forked ribs 42 and 43 are positioned on the diaphragm 36 in a manner similar to the manner in which the forked ribs 12 and 13 are positioned on the diaphragm 1. However, in the diaphragm 36, the main branches 44 and 47 of the forked ribs 42 and 43, respectively, extend a distance of approximately one-half the distance between the tubular member 46) and the ends '7 and 8, respectively, and the end branches 45 and 46 and 43 and 49, therefore, project only approximately one-fourth of the distance between the tubular member it) and the ends 7 and 8 of the vibratile portion 37.

The vibratile portion 37 of the diaphragm 36 embodies portions 50, 51, 52, 53, 54 and 55 which are positioned and shaped similarly to the portions 22-27, respectively, of the diaphragm 1. The principal difference in the portions 50-55 and the portions 22-27 is one of size, the portions 50 and 53 being smaller in size than the portions 22 and 25, respectively, and the portions 23, 24, 26 and 27 being smaller in size than the portions 5-1, 52, 54 and 55, respectively.

As shown in the drawings, the diaphragm 36 is somewhat longer than the diaphragm 1. However, it will be appreciated by those skilled in that art that this is merely by way of illustration rather than by way of limitation and that diaphragms of any practical size may be con structed without departing from the purview of my invention.

One of the principal differences between the diaphragm 36 and the diaphragm 1 is that the flange 39, which is rectangular in shape, extends completely around the vibratile portion 37 without any complete interruptions therein such as at the corners 34 of the flange 4 of the diaphragm 1. The flange 39, like the flange 4, embodies an outer edge portion 32 connected to an inner edge portion 33 by an undulated portion 38, Fig. 5. The inner edge portion 33 of the flange 39 is attached to the outer flange 20 of the outer edge 6 of the diaphragm 36, in a manner similar to that heretofore discussed with respect to the diaphragm 1, and the outer edge portion 32 of the flange 39 may be suitably clamped between supporting braces, or the like, in a speaker with the vibratile portion 37 movably supported on the flange 39 by the undulated portion 38 A plurality of openings 56 are formed in the flange 39. Each of the openings 56 as shown in the drawings, extends through the inner edge portion of the outer edge portion 32 of the flange 39 and through the outer edge portion 38a of the undulated portion 38 of the flange 39. Each opening 56 is positioned directly outwardly from a respective one of the corners of the vibratile portion 37 on what would constitute an outward extension of a line bisecting the angle between the two sides of the vibratile portion 37 forming the respective corner. The openings 56 are preferably round in shape, but as will be appreciated by those skilled in the art, openings of other shape may be used Without departing from the purview of my invention.

It has been found that with openings such as the openings 56 formed in the flange 39 of a diaphragm such as the diaphragm 36, a diaphragm having good sound reproducing characteristics, and wherein the vibratile portion thereof vibrates substantially as a unit is afforded. Also, it has been found that this construction tends to eliminate the cracking and breaking out of the corners of such diaphragms. It is presently believed that these resuits are obtained because the openings 56, when they are extended through at least a portion of the undulated portion 38, permit the adjacent end and side portions of the vibratile portion 37 to flex and vibrate as a unit, to thereby improve the tone reproducing qualities of the diaphragm and to eifectively reduce the tendency of the diaphragm to tear at the corners.

In Fig. 8 a modified form of diaphragm 57 is shown which is identical in construction to the diaphragm 1, except that the strips forming the flange 4, and the underlying flange portions 20 of the vibratile portion 2 are extended longitudinally so that the adjacent ends of adjacent ones of the strips such as, for example, the strips 28 and 30 shown in Fig. 8, are not disposed perpendicularly to each other as in the diaphragm 1, but are disposed at a relatively small acute angle to each other of approximately ten degrees. The openings 53 thus formed at the corners of the diaphragm 57 extend through the flange 4, and afford a modified form of the relieved corners 34- of the diaphragm 1.

Such construction is also effective to permit the adjacent sides of the vibratile portion 2 to vibrate as a unit, and to effectively tend to prevent the corners of the diaphragm 57 from cracking or breaking out.

It will be seen that in each of the forms of the invention shown in the drawings, openings are formed in the outwardly projecting mounting rim, outwardly of each of the corners of the vibratile portion supported by that rim. Each of these openings projects at least partially through the undulated portions of the mounting rims, and it is presently believed that this construction and location of the openings is an important aspect of the present invention.

It will be seen that although the diaphragms shown in the accompanying drawings are rectangular elongated diaphragms, my invention is not limited thereto, and is equally applicable to other polygonal-shaped diaphragms having corners such as, for example, square-shaped diaphragms, triangular-shaped diaphragms, and the like.

Also, it will be understood by those skilled in the art that although the diaphragms shown herein have flange portions which are separate from, and attached to the vibratile portions, this is merely by way of illustration and not by way of limitation, and that diaphragms may be constructed wherein the flange portions are formed integral to the vibratile portions without departing from the purview of the present invention.

Thus, while I have illustrated and described the preferred embodiments of my invention, it is to be understood that these are capable of variation and modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. An acoustic diaphragm comprising a polygonalshaped vibratile portion, and flexible mounting means attached to and projecting outwardly from said vibratile portion, said mounting means having undulations therein disposed outwardly of said vibratile portion in substantially parallel relation thereto, said mounting means also having openings extending through the outer edge portions of said undulations outwardly of the corners of said vibratile portion in the planes bisecting the angles of said corners.

2. An acoustic diaphragm comprising a polygonalshaped vibratile portion, and flexible mounting means attached to and projecting outwardly from said vibratile portion, said mounting means having undulations therein disposed outwardly of said vibratile portion in substantially parallel relation thereto, said mounting means also having openings extending through the outer edge portion of said undulations outwardly of the corners of said vibratile portion in the planes bisecting the angles of said corners, said openings terminating in spaced relation to the outer edge of said mounting means and the outer edge of said vibratile portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,930,328 Tichenor et a1. Oct. 10, 1933 2,020,705 Stenger Nov. 12, 1935 2,685,935 Lenz Aug. 10, 1954 2,820,527 Bobb et a1. Jan. 21, 1958 

